The embodiments described herein relate to an ultrasonic image display apparatus power circuit and an ultrasonic image display apparatus.
An ultrasonic image display apparatus displays an ultrasonic image based on an echo signal acquired by transmitting an ultrasonic wave. To transmit an ultrasonic wave, the ultrasonic image display apparatus applies a voltage to an ultrasonic transducer made of a piezoelectric material and oscillates the ultrasonic transducer. Accordingly, the ultrasonic image display apparatus is provided with a power circuit that supplies transmission power for the ultrasonic wave. For example, see Japanese Patent Application Laid Open No. 2010-029657.
The ultrasonic image display apparatus transmits an ultrasonic wave using some of ultrasonic transducers provided for an ultrasonic probe. An analog switch is provided for selecting an ultrasonic transducer used for the ultrasonic wave transmission. Accordingly, the ultrasonic image display apparatus is also provided with a power circuit that supplies a bias voltage for the analog switch.
Conventionally, in many cases, the power circuit for ultrasonic transmission power is provided independently of the power circuit for bias power. This bottlenecks circuit miniaturization.
For example, a flyback converter is often used as the power circuit for ultrasonic diagnostic equipment. However, the power circuit using the flyback converter uneconomically consumes power due to a resistance load when a high voltage changes to a low voltage. The power circuit using the flyback converter may require a circuit for consuming power when a high voltage changes to a low voltage. This bottlenecks circuit miniaturization. As a limitation, the flyback converter can use only low frequencies.